1. Field
This invention relates to the treatment of solid fuels, and more particularly, treatment of solid fuels using microwave energy to remove contaminants and reduce moisture content.
2. Description of the Related Art
The presence of moisture, ash, sulfur and other materials in varied amounts in all solid fuels generally results in inconsistencies in fuel burn parameters and contamination produced by the burning process. The burning of solid fuels may result in the production of noxious gases, such as nitrous oxides (NOx) and sulfur oxides (SOx). Additionally, burning solid fuel may result in the generation of inorganic ash with elements of additional materials. Amounts of carbon dioxide (CO2) that are generated as a result of burning solid fuels may contribute to global warming. Each of these byproducts will be produced at varying levels depending on the quality of the solid fuel used.
The presence of moisture in varied amounts in solid fuels generally reduces the power output of the solid fuel upon combustion. Reduction of the moisture content of the solid fuel may allow for increased thermal efficiency upon combustion. Increasing the thermal efficiency of solid fuel combustion may result in lower costs for power generation because less fuel is needed. Increased thermal efficiency may also reduce other emissions generated during combustion, such as those of SO2 and NOx.
Various processes have been used in the treatment of solid fuels such as washing, air drying, tumble drying, and heating to remove some of the unwanted materials that are be present in the solid fuels. These processes may require the solid fuel to be crushed, pulverized, or otherwise processed into a size that is not be optimum for an end-user. To further reduce emissions, exhaust scrubbers may be used at the combustion facility. There exists a need to further reduce the moisture content of solid fuel and the harmful emissions produced as a result of burning solid fuels and reduce the costs associated with the control of such emissions.